I just got a CO2 tank on Sunday and got it filled for the first time today. I watched the guy and it seemed like he put only 10lbs in there as I was watching the scale, but just a few minutes ago the pressure relief valve blew on it. It's on the Jeep right now parked and the sun started hitting it about 20 minutes before it went, but I can't see how the sun hitting it could heat it that much, maybe I'm worng, but can anyone with knowledge of this suggest if it was overfilled coupeld with the sun, just overfilled or just the sun? BTW it's about 89 outside right now.

 

It happened to my buddy's the other day. When you put 20+ lbs. in a 10lb tank, the pop-off valvue will releive it. His tank was sitting in the sun as well.

Have someone refill it and ask them to pay attention this time.

 

It's a 10# tank and it was filled with 10#'s or at elast that's what it looked like on teh scale. The tank is about 20lbs and when he finished it was about 30lbs, but it was an old scale, so who knows if it's accurate, but the tanf manufacturer says it should be 20lbs empty,

 

when gasses heat they expand
its normal

 

yes, I understand that, but if this is going to be for my Jeep in the desert and it's going to blow when it's only 89 and the bottom 1/3 of the tank has sun on it, then I may need to return it, but I know others that have them with no issues, so I'm just trying to figure out if I should go beat on the place where I got it filled to refill the tank and put less in or do i possibly have a faulty valve. Just wondering if someone out there with more knowledge of CO2 might understand what's happend.

Per Ultimate Air's website, the tank is fine to around 115 to 130 degrees ambient air temperature, but with sun on it, I can see it getting that hot, but just wondering if others have had this happen.

 

I only put about 8lbs in my tank and it has sat outside in 120+ degree weather and has never blew a relief valve... I would guess that it was overfilled.

 

Liquid co2 has an ambient temperature of a negative 109 degrees. When a new (empty) tank is filled the liquid co2 needs to take the internal temp of the tank down to a minus 109 before it will actually start to fill the tank. As the cold liquid hits the warm tank it converts to gas and starts to build pressure inside the tank. A co2 tank is a "low" pressure tank, meaning it is meant to hold 500psi vs 2400 psi of a high pressure tank. After the tank is filled and the tank temp and pressure equalize, the high limit will vent off any excess pressure. This is normal and a good thing so you do not have to much pressure in the tank.

Now that you have filled it unless you let the tank go bone dry again it should not be a problem.

As for sitting in the dessert and the heat causing you to lose co2.....unless it gets in the 125 to 130 range you should be fine. Once a tank is full, the pressure keeps the liquid a liquid, barring extreme temps you will be fine. Even if it does get extremely hot, it will just vent off enough to get the pressure back down to a safe level.

another thing to be aware of....around the top of the tank you will see a TARE weight....this is what the tank weighs empty, so you can use a bathroom scale to get a real good idea of how much co2 is in the tank.

 

Thanks BaltChief, if I'm reading that right, it could be an issue becasue it was new and had never been filled before, hopefully that is the case. thanks

 

I don't know much about CO2 tanks, but I know with most propane tanks they need to vacuum the inside out prior to filling the first time. Could this be part of the reason?

 

I might have found the problem, according to Ultimate-Air's website, they say a 10# tank weighs about 20lbs, but I just weighed it now that it's empty and it's only 13lbs. I know the tank was 30 whe nhe finished filling it, so I'm guessing he put like 17lbs in, not 10, which would certainly put too much pressure. Going to call them Monday and see if they will fill for free due to their error. Thanks everyone fo rthe info.